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Re: [Tauruslib-users] Maximum required time to update Taurus label.
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From: Carlos P. <cpa...@ce...> - 2015-07-21 22:14:32
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Hi Binit, ATK does its own reads (it does not wait for the tango polling events), and without further details about how you do it on the "command line", I must assume that you refer to doing explicit calls to read_attribute on a PyTango.DeviceProxy (which would be equivalent to what ATK is doing). So, it looks like the problem is that you are not properly activating the Tango polling period for the attribute you want to read in your DS, and taurus is simply using its own polling period in absence Tango polling. Please report the output for both of the attached scripts (edit the device and attr names first to match your own!). If testpolling1,py reports that the attribute is not polled, make sure that you followed my instructions from the previous email... and if that doesn't work, contact the Tango mailing list for help on how to activate the Tango polling, because I am out of ideas. Cheers, Carlos On Tue 21 July 2015 11:15:27 Binit Amin wrote: > Hi Carlos, > > >In order to have polling events sent, you have to: > >a) set a polling period (see e.g. "float_scalar" in snapshot1.png) > >b) set the thresholds (see e.g. "float_scalar" in snapshot2.png) > > I had already done the same settings on my Jive DS. It reflects > changes on the ATK panel as well as on the command line, but still > GUI takes 3 sec to updates Taurus label. > > I want to update my GUI also on every seconds not only the Jive ATK > panel. Your suggested procedure won't update GUI on every second. > >(...) > > > > taurus.changeDefaultPollingPeriod(period_in_ms) > > > > -- This works as expected. It updates GUI as well as command line in > > one second as I have set: taurus.changeDefaultPollingPeriod(1000) > > > > Regarding your suggestion to set the pooling period of 1 second in > > jive, I tried that but It seems problem in updating GUI, where as > > command line is updating in every one second. I don't know what did > > i > > missed when I set pooling period in jive 1000 ms. > > (...) > > There is one "hidden" trick about Change events in Tango: Tango will > only send a change event if the value has changed more than some given > relative or absolute thresholds. > These thresholds can be set via jive for the attributes of a device > going to the "Event" branch of the device-->"Change event" tab (see > attached snapshot) > > By default, the thresholds are set to None, so no events get > processed. > > In order to have polling events sent, you have to: > a) set a polling period (see e.g. "float_scalar" in snapshot1.png) > b) set the thresholds (see e.g. "float_scalar" in snapshot2.png) > > > I hope this helps, > > Carlos > > > -- > > Thanks & Regards > > Binit Amin > > Assistant System Engineer > > TATA Consultancy Services > > Cellno: +91-7276974159 > > Mailto: bin...@tc... > > Website: http://www.tcs.com > > > > > > ----- Original Message ----- > > From: "Carlos Pascual" <cpa...@ce...> > > To: tau...@li... > > Cc: "Nexeya TANGO Team" <TA...@ne...>, "Binit Amin" > > <bin...@tc...> Sent: Wednesday, July 8, 2015 12:19:26 PM > > Subject: Re: [Tauruslib-users] Maximum required time to update > > Taurus > > label. > > > > > > Hi, I just want to give some extra information about polling in > > Taurus: > > > > As Sebastien said, the default polling period of taurus is 3s and > > can > > be changed with > > > > taurus.changeDefaultPollingPeriod(period_in_ms) > > > > The above will set the taurus polling period (i.e. an active > > periodic > > read by the *client*). This affects to *all* attributes for the > > given > > client, and therefore setting it to a too short period if the client > > connects to a lot of servers may not be a good idea (note: taurus > > optimizes the polling by reading all attributes from a given device > > at once). > > > > But taurus polling is not the only way to go: you can use the Tango > > polling system (i.e. at server level), which can be configured > > independently for each attribute of a device via jive. See section > > 9.2 of [1]. Note that in this case, the polling will be set at > > attribute level *but for all clients*. > > > > Apart from that, it is always worth to consider programming your > > device servers to push events (see section 9.4 of [1]). This way, > > instead of periodic polling you will get updated values as soon as > > they change and you save bandwidth when the values do not change. We > > at Alba push events in devices such as motors in which we want to > > see > > very quick updates of the position when they are moving but which > > may > > stay at one position without moving for months. > > > > Taurus handles this "intelligently" and it will only activate its > > own > > polling for a given attribute if neither Tango polling is active nor > > events are pushed at the server. > > > > > > [1] > > http://www.esrf.eu/computing/cs/tango/tango_doc/kernel_doc/ds_prog/n > > od e10.html > > > > I hope that helps. > > > > Cheers, > > > > Carlos > > > > On Tue 7 July 2015 12:11:16 Nexeya TANGO Team wrote: > > > Hi, > > > > > > There is a method for changing the polling period which is 3s by > > > default. > > > > > > You will have to insert this into your application. > > > Import taurus # if it isn’t already imported > > > taurus.changeDefaultPollingPeriod(500) > > > > > > > > > Sébastien GARA > > > Ingénieur d'études - Formateur TANGO > > > NEXEYA SYSTEMS > > > Une société de NEXEYA > > > 24 Avenue de Pasleck > > > CS 30019 > > > 16400 La Couronne > > > ---------------------------------- > > > Tel: 33 (0)5.45.24.22.36 > > > Afin de contribuer au respect de l'environnement, merci de > > > n'imprimer > > > ce courriel qu'en cas de nécessité. > > > > Ce message et les fichiers > > > > > pouvant être attachés sont confidentiels, réservés à l'usage > > > unique > > > des destinataires et n'engagent NEXEYA sous aucune forme que ce > > > soit. > > > This email and any files transmitted with it are confidential, > > > intented solely for the unique use of the recipients and don't > > > commit > > > NEXEYA. > > > De : Binit Amin [mailto:bin...@tc...] > > > Envoyé : mardi 7 juillet 2015 12:13 > > > À : tau...@li... > > > Objet : [Tauruslib-users] Maximum required time to update Taurus > > > label. > > > > > > Hello All, > > > > > > I want to know, what is the maximum time taurus label takes to > > > update > > > its values, when it is connected with the device server. Because > > > when > > > I connecting my taurus label it takes little bit time to update > > > its > > > value. > > > > > > For checking purpose I try using one clock Programming and update > > > taurus label and It's maximum of 3 sec in my system. > > > > Is this correct > > > > > delay period for each system or is this time period is system > > > dependent, because I had tried on other system also. and it is > > > same. > > > If yes then is there any way to decrease that delay time to 1 > > > second?? > > > > > > FYI I am using Fedora 19, PyQt 4.11.3, Python 2.7.5, PyTango 8.1.5 > > > Attachment includes the video of displaying delay in time because > > > of > > > refreshing period of taurus label. > > > > > > Any help is appreciable. > > > > > > -- > > > Thanks & Regards > > > Binit Amin > > > Assistant System Engineer > > > TATA Consultancy Services > > > Cellno: +91-7276974159 > > > Mailto: bin...@tc...<mailto:bin...@tc...> > > > Website: http://www.tcs.com > > > > > > =====-----=====-----===== > > > Notice: The information contained in this e-mail > > > message and/or attachments to it may contain > > > confidential or privileged information. If you are > > > not the intended recipient, any dissemination, use, > > > review, distribution, printing or copying of the > > > information contained in this e-mail message > > > and/or attachments to it are strictly prohibited. If > > > you have received this communication in error, > > > please notify us by reply e-mail or telephone and > > > immediately and permanently delete the message > > > and any attachments. Thank you > > > > -- > > +----------------------------------------------------+ > > > > Carlos Pascual Izarra > > Scientific Software Coordinator > > Computing Division > > ALBA Synchrotron [http://www.albasynchrotron.es] > > Carretera BP 1413 de Cerdanyola-Sant Cugat, Km. 3.3 > > E-08290 Cerdanyola del Valles (Barcelona), Spain > > E-mail: cpa...@ce... > > Phone: +34 93 592 4428 > > > > +----------------------------------------------------+ > > > > -- > > Thanks & Regards > > Binit Amin > > Assistant System Engineer > > TATA Consultancy Services > > Cellno: +91-7276974159 > > Mailto: bin...@tc... > > Website: http://www.tcs.com -- +----------------------------------------------------+ Carlos Pascual Izarra Scientific Software Coordinator Computing Division ALBA Synchrotron [http://www.albasynchrotron.es] Carretera BP 1413 de Cerdanyola-Sant Cugat, Km. 3.3 E-08290 Cerdanyola del Valles (Barcelona), Spain E-mail: cpa...@ce... Phone: +34 93 592 4428 +----------------------------------------------------+ |
